RockHoundBlog

Druze and Drusy

Filed under: Rockhound Dictionary,Video — Gary October 14, 2010 @ 9:57 am

Rockhound Terms

Drusy
Drusy (sometimes referred to as: druse, druzy) is a layer of tiny quartz crystals that form on a host stone (A gemstone with natural surface textured similar to fine sugar crystals.). The cavity inside a geode is sometimes filled with drusy quartz crystals. Although the quartz crystals may be the source of the color (amethyst, citrine), usually it is the host stone’s color (chrysocolla, uvarovite garnet) that shows through the quartz and gives the stone its color. (pronounced: dru-zee).  Drusy is created by the phenomena of micro-crystalline facets forming on a gem and the surrounding rock, they were formed naturally millions of years ago.

Druze
Druze is a layer of crystals that form within a mineral crust, like the inner cavity of a geode. Amethyst crystals are often found in a druze. The inner cavity of agate geodes are often lined with a druze of sparkling quartz crystals.

Lets call the whole thing off?  :)

RockHound Term

Filed under: Rockhound Dictionary,Video — Gary October 13, 2010 @ 10:15 pm

Chatoyancy

Chatoyancy

Chatoyancy

In gemology, chatoyancy (pronounced shə-TOY-ən-see), or chatoyance, is an optical reflectance effect seen in certain gemstones. Coined from the French “œil de chat,” meaning “cat’s eye,” chatoyancy arises either from the fibrous structure of a material, as in tiger eye quartz, or from fibrous inclusions or cavities within the stone, as in cat’s eye chrysoberyl. The effect can be likened to the sheen off a spool of silk: The luminous streak of reflected light is always perpendicular to the direction of the fibres. For a gemstone to show this effect best it must be cut en cabochon, with the fibers or fibrous structures parallel to the base of the finished stone. Faceted stones are less likely to show the effect well.

Gem species known for this phenomenon include the aforementioned quartz, chrysoberyl, beryl (especially var. aquamarine), tourmaline, apatite, moonstone and scapolite. Glass optical cable can also display chatoyancy if properly cut, and has become a popular decorative material in a variety of vivid colors.

The term Cat’s Eye, when used by itself as the name of a gemstone, can only be used to refer to a Cat’s Eye Chrysoberyl. Any other stone exhibiting this phenomenon must have the stone’s name after the Cat’s Eye identifier, i.e. Cat’s Eye Aquamarine.

Chatoyancy can also be used to refer to a similar effect in woodworking, where certain finishes will cause the wood grain to achieve a striking three-dimensional appearance. This effect is often highly sought after, and is sometimes referred to as “wet look”, since wetting wood with water often displays the chatoyancy, albeit only until the wood dries. Oil finishes and shellac can bring out the effect strongly.

Interesting video  – How light reacts with a gemstone


Utah Ice

Filed under: Mineral of the day,Video — Gary @ 8:38 pm

Someone asked me if I ever heard of the mineral “Utah Ice”.  Hmph I said…  After some digging (no pun intended) this is what I came up with.

Question:

This stuff looks almost like glass, specially when it gets into the water it looks alot like glass, but its not.
My warning is, that you shouldn’t buy it for the aquarium.
Why?
Well I bought a load of it for my 29gal, and guess what? Its all gone!
Yes, thats right.. it slowly dissolved away, over about 5 months some very large pieces are down to tiny little slivers.
Just a heads up, don’t buy it unless you want to have to KEEP buying it.

Selenite, a crystalline form of gypsum

Selenite, satin spar, desert rose, and gypsum flower are four varieties of gypsum; all four varieties show obvious crystalline structure. The four “crystalline” varieties of gypsum are sometimes grouped together and called selenite.

All varieties of gypsum, including selenite and alabaster, are composed of calcium sulfate dihydrate (meaning has two molecules of water), with the chemical formula CaSO4·2H2O.

Identification of gypsum

All varieties of gypsum are very soft minerals (hardness: 2 on Mohs Scale). This is the most important identifying characteristic of gypsum, as any variety of gypsum can be easily scratched with a fingernail. Also, because gypsum has natural insulating properties, all varieties feel warm to the touch.

Varieties

Though sometimes grouped together as “selenite”, the four crystalline varieties have differences. General identifying descriptions of the related crystalline varieties are:

Selenite

Selenite

Selenite

  • most often transparent and colorless: it is named after Greek σεληνη= “the moon”.
  • if selenite crystals show translucency, opacity, and/or color, it is caused by the presence of other minerals including druse (a coating of small crystal points)
  • druse is the crust of tiny, minute, or micro crystals that form or fuse either within or upon the surface of a rock vug, geode, or another crystal

Satin spar

  • most often silky, fibrous, and translucent (pearly, milky) – can exhibit some coloration
  • the satin spar name can also be applied to fibrous calcite (a related calcium mineral) – calcite is a harder mineral – and feels greasier, waxier, or oilier to the touch.

Desert rose

  • rosette shaped gypsum with outer druse of sand or with sand throughout – most often sand colored (in all the colors that sand can exhibit)
  • the desert rose name can also be applied to barite desert roses (another related sulfate mineral) – barite is a harder mineral with higher density

Gypsum flower

  • rosette shaped gypsum with spreading fibers – can include outer druse
  • the difference between desert roses and gypsum flowers is that desert roses look like roses, whereas gypsum flowers form a myriad of shapes

Use and history

Selenite mine

Selenite mine

Because of the long history of the commercial value and use of both gypsum and alabaster, the four crystalline varieties have been somewhat ignored, except as a curiosity or as rock collectibles.

Crystal habit and properties

Crystal habit refers to the shapes that crystals exhibit.

Selenite crystals commonly occur as tabular, reticular, and columnar crystals, often with no imperfections or inclusions, and thereby can appear water or glass-like. Many collectible selenite crystals have interesting inclusions such as, accompanying related minerals, interior druse, dendrites, and fossils. In some rare instances, water was encased as a fluid inclusion when the crystal formed.

Selenite mine

Selenite

Selenite crystals sometimes form in thin tabular or mica-like sheets and have been used as glass panes.

Selenite crystals sometimes will also exhibit bladed rosette habit (usually transparent and like desert roses) often with accompanying transparent, columnar crystals. Selenite crystals can be found both attached to a matrix or base rock, but can commonly be found as entire free-floating crystals, often in clay beds (and as can desert roses).

(more…)

ThunderEgg Cutting

Filed under: Video,how to? — Gary October 12, 2010 @ 8:54 pm

Cool video I found of someone cutting a ThunderEgg.

As well  did a story on OregonThunderEggs.com a while ago.  Here is a video they put together.  Pretty interesting!

Thunderegg Hunting in Oregon

Florida Rockhounding

Filed under: Coming Events,Rockhound Travel — Gary @ 8:47 pm
Miami-rockhound

Miami-rockhound

October 16, 2010

Join MiaSci and the Miami Mineralogical Lapidary Guild for the annual Gem and Mineral Show! This year we will feature pieces from the Smithsonian’s “American Gemstone Jewelry Collection”. Visitors will also enjoy an array of classes, workshops and demos as well as have the opportunity to interact with vendors and enthusiasts.

Site: http://miamisci.org/

Gem and Mineral Show
Join MiaSci and the Miami Mineralogical Lapidary Guild for the annual Gem and Mineral Show! This year we will feature pieces from the Smithsonian’s “American Gemstone Jewelry Collection”. Visitors will also enjoy an array of classes, workshops and demos as well as have the opportunity to interact with vendors and enthusiasts.

Time: 10am – 6pm
Location: Miami Science Museum
Phone Contact: Box Office 305.646.4200
Email Contact: boxoffice@miamisci.org

Miami Mineralogical & Lapidary Guild Demos
Interested in gems, minerals, & fossils? Come check out the Miami Mineralogical & Lapidary Guild club demonstrations and exhibits the 4th Sunday of every month (excluding December). See live demonstrations of cutting gemstones, making jewelry, showcases of what you can collect on field trips & vacations, crystal identification, and much more! Hours are 1-4 p.m. in Classrooms A&B.

Time: 1:00 pm – 4:00 pm
Location: Classrooms A&B
Phone Contact: Karlisa Callwood 305-646-4233
Email Contact: kcallwood@miamisci.org

PENNSYLVANIA Rockhounding

Filed under: Rockhound Travel — Gary @ 8:14 pm

PENNSYLVANIA

Crystal-Point-Diamond-Mines

Crystal-Point-Diamond-Mines

Crystal Point Diamond Mines

1307 Park Avenue
Williamsport, PA 17701
Ph. (570) 323-6783 Fax (570) 321-7374
Email: rpsmith@csrlink.net

The owner guarantees if you’re not afraid to work, you won’t be disappointed with a 2.5 gallon bucket of quality crystals or clusters. For the lazy man or woman, dig in the tailings for the same results. Open April-October, by appointment only. Kids welcome, with close adult supervision. Ray Smith, owner/operator. $40 adults. $20 kids under 12.

Crystal-Point-Diamond-Mines_map

Crystal-Point-Diamond-Mines_map

Welcome to Crystal Point Diamond Mines, one of the largest quartz deposits ever found on the East coast. Located just outside of Williamsport, Pennsylvania, this fee-dig mine has been visited by people from all over the world. The mine is usually open to collectors from May through October. Rockhound clubs and other groups as well as children are accommodated. The quartz crystal points, resembling diamonds, are very plentiful and easy to dig.  Most of your time is spent deciding which ones to keep.  If you don’t like to dig, there are plenty around to sift out of the dirt or just pick up.

cluster_crystals

cluster_crystals

Ray_smith

Ray Smith owner

crystal_cavities

crystal_cavities

I have been told that this mine might be closed.  Can anyone comment on this?

UPDATE:

Crystal Point Diamond Mines is Temporarily closed by the PA Department of  Environmental Protection- Bureau of Mines

Watch for further NOTICE!!

Sheffield mine

Filed under: Rare Rocks!,Rockhound Travel,Video,rockhounding maps — Gary October 8, 2010 @ 10:07 pm

Sheffield Mine
385 Sheffield Farms Rd
Franklin, NC 28734
Ph. (828) 369-8383
E-mail: ruby@sheffieldmine.com
Website: www.sheffieldmine.com
Native star rubies at Sheffield mine in Franklin, NC. Novice and experienced rock hounds welcome! 488 carat ruby found in 2002! Look for native rubies or for gemstones from around the world. We supply all necessary tools Rock & gift shop open 10am daily, April thru October. Group rates available.

Ruby Video

Video

How do I find Rubies &  Sapphires?

1-Pick out a bucket that has rubies in it!
I know – they all look the same!  So good luck!!!
2-Pour no more than 1/8th to 1/4 of a bucket of dirt into your tray at one time.  If you pour in more dirt, you will have so many rocks that you won’t be able to see anything but rocks and more rocks – your rubies will probably be playing hide and seek under the ton of gravel in your tray and the more you roll them around the sneakier at hiding they will become!
3-Immerse the tray into the water and moosh around the dirt and break up any mud-balls! This is the time to get your hands muddy – don’t be afraid!    You won’t melt in the water and the dirt is only temporary – you will someday be clean again – promise!
4-Bring your tray out of the water and rest it on the edges of the flume.  Now move the larger stones to one end of the tray and put the rest of the stones into a circle in the center of the tray and using one or both hands, roll them around. Don’t press hard – no need to hurt yourself!  The rocks will bang against each other and knock dirt off for you.  Let them do most of the work!
5-Put the tray back into the water and rinse off the mud that you just scrubbed off.
6-Bring the tray out of the water again and gather the smaller stones to the center and roll them around again.
7-Repeat Steps 5 thru 6 about 3 more times, or until you no longer see mud coming off of the stones and your hands don’t seem muddy any more either! Do not fail to complete this step!!!
8-Now it’s time to look for rubies and sapphires!  Oh, 1 hint – SUN LIGHT helps – a lot!!!!!! Spread the stones out in the tray so that there aren’t rocks sitting on top of other rocks.  Look for a Pink, Purple of Reddish hue.  Look for a glossy surface.  A ruby or sapphire will be heavier than an ordinary rock of the same size.  A ruby or sapphire will not fall apart or impart a pigment on the screen bottom when youn try to scratch the tray.  They will make a scratchy noise.  But so will quartz – quartz is orange, or brown, much like the dirt, but rubies and sapphires have a different look about them.  Our sapphires tend to be in the pink/white category, so you probably won’t find any blue ones – sorry – but the pink ones are beautiful too! You might be fortunate and find one that has the classic 6 sides. Any or all of the above can indicate that you have found a ruby or sapphire!  If you are sure of it, put it in your film canister, if you are unsure, put it in the tin can & we will help you to identify it!

We’re having
an AWESOME
2010 Season!

Ruby Mining

Ruby Mining

As of 7-26-10
414 Honkers have been found along with
14 Super Honkers
& there’s lots more in the dirt still waiting to be found!!

record_ruby

record_ruby

sheffield_mine_map

Sheffield Mine map

Directions -
From Downtown Franklin – Take Hwy. 28 North.  Cross the river, pass the Cowee Baptist Church and right across from the BP Gas Station you’ll turn right onto Cowee Creek Rd., (the first asphalt road on the right past the church – you’ll see a sign for Perry’s Water Garden). Pass Cowee Elementary School and bear right at the first Y in the road and you’ll pass Rickman’s General Store. and then go left at the second Y in the road – which is Leatherman Gap Rd.  About 200 yards on the left is our entrance. Big Sign – Can’t miss it!  At this point you are only 1/2 mile from the parking lot!
From Asheville -
Take I-40 West and get off at Exit 27.This puts you going in the correct direction with no choices on your part until you get to Exit 81 (Atlanta, Franklin, Dillsboro exit). Take Exit 81 and you will be put onto Hwy 441 – no directional choices – you will be going SOUTH. At this point, you are approximately 30 to 40 minutes from us. At some point, you will start up a steep incline and eventually, you will start down a steep incline and when you start to see civilization again and when you stop riding the brakes (oh yeah, it is a steep incline!) then look to the RIGHT. You’ll see Mountain City Mobile Homes. Right there is a road named Sanderstown Rd. Turn Right there and stay on Sanderstown Rd until it ends! Turn Right again (now you are on Bryson City Rd aka Hwy 28). You are not in downtown Franklin, but now you need to Follow directions from Downtown Franklin.
From Cherokee -
Go South on US 441 and turn right onto Sanderstown Rd.  You’ll know that you are at Sanderstown Rd. because there is Showcase Mobile Homes on one corner and Burglens Rock Shop on the other.  Follow Sanderstown Rd. all the way to it’s end and turn right onto Hwy 28 North and follow directions as if coming from Franklin.  Don’t look for the river – you’re already past it.
From Atlanta – Follow US 441 North into Franklin, then turn right onto Main Street.  You’ll immediately turn left onto Hwy 28 North.  Now follow directions from Franklin.
From Chatanooga – Follow Hwy 64 East to US 441 North and turn left.  Follow directions as if coming from Atlanta.

From Nashville & Knoxville Take I-40 East to Exit #27 (the second Waynesville Exit also known as the Clyde Exit).  Now follow directions as if coming from Asheville.